Machine Shop Research Articles

Impact of 6S (5S+Safety) Implementation in Machine Workshops on Occupational Safety

In this current study, the impact of implementing 6S (5S+Safety) in the machining industry on occupational safety was investigated by selecting the chip machining section of a factory producing flywheels. To facilitate the comparison of risk levels before and after the implementation of 6S, a Fine-Kinney risk evaluation was conducted in the sawdust department before the application of 6S. The 6S implementation process took 28 days, and subsequently, a Fine-Kinney risk evaluation was performed in the sawdust department, revealing a 77.4% reduction in risks. As a result, the 77.4% reduction in accident risks indicates that the implementation of 6S, which emphasizes safety within the framework of the 5S principles, leads to a more organized, cleaner, and safer machine workshop environment. We can indicate that this approach not only reduces the risk of accidents but also enhances work efficiency, preventing time loss and material waste.

Exploration of weak-PGML Method for Efficient Stability Control During Machining Operations

Stable control of the machining process can be difficult to maintain in production environments due to many factors, but especially uncertainty about selection of optimal machining parameters. The true underlying stability model for production machines on the shop floor is generally unknown, so parameters are typically selected by operators based on manufacturer recommendations or, in most cases, their accumulated shop floor experience. A class of methods referred to as physics-guided machine learning (PGML) offers a new approach for optimal parameter selection that incorporates theoretical knowledge about machining dynamics into the data-driven machine learning workflow. The focus of this paper is a version of PGML appropriate to shop floor operations in small and medium-sized machine shops (SMMs)—referred to as weak-PGML—that does not require a priori theoretical knowledge of machining dynamics to approximate the true underlying stability model for a particular machining scenario. Rather, the weak-PGML leverages the operator’s accumulated domain knowledge to uncover the true stability model and informs parameter selection. Weak-PGML reflects the limited resources and lack of technical expertise typical of most SMMs with legacy machines and a new generation of workforce without the accumulated experience of operators who have spent many years on the shop floor.

TWINKLE: An open-source two-photon microscope for teaching and research.

Many laboratories use two-photon microscopy through commercial suppliers, or homemade designs of considerable complexity. The integrated nature of these systems complicates customization, troubleshooting as well as grasping the principles of two-photon microscopy. Here, we present "Twinkle": a microscope for Two-photon Imaging in Neuroscience, and Kit for Learning and Education. It is a fully open, high-performance and cost-effective research and teaching microscope without any custom parts beyond what can be fabricated in a university machine shop. The instrument features a large field of view, using a modern objective with a long working distance and large back aperture to maximize the fluorescence signal. We document our experiences using this system as a teaching tool in several two week long workshops, exemplify scientific use cases, and conclude with a broader note on the place of our work in the growing space of open-source scientific instrumentation.

Repositioning of an Engineering Works Complex as an Industrial Hub for Spare Parts and Components Production

Ajaokuta Steel Company Limited (ASCL) comprises several units, including the Engineering Works Complex, which is one of the key auxiliary units of the steel plant. This complex is equipped with the necessary tools and machinery for producing fixtures and spare parts that meet a wide range of requirements. These machines are operated by welltrained engineers, skilled technicians, and artisans. The complex is designed to carry out repairs on equipment across the entire steel plant, as well as to manufacture spare parts for external agencies. Additionally, facilities are available for training technicians and artisans. The Engineering Works Complex consists of five major workshops: the Machine and Tools Shop, Forge and Fabrication Shops, Foundry and Pattern Making Shops, Power Equipment and Repair Shops, and the Rubberizing Shop. It is fully equipped to meet the industrial demand for spares and consumables, and it has the capacity to serve as a research institution where modern research can be conducted. This research aims to explore the potential of repositioning the Engineering Works Complex at Ajaokuta Steel Company as a leading industrial hub for the production of spare parts and components in Nigeria. The study will analyze the potential economic benefits of this repositioning, such as increased employment opportunities, higher productivity, and greater contributions to the national economy. By drawing on case studies from other countries that have successfully developed their engineering sectors, the research will provide insights and lessons that can be applied to the Nigerian context. The Engineering Works Complex is actively utilizing the government's local content policy to achieve these goals. With the necessary attention, including adequate funding for the various shops within the complex, it could generate significant revenue and create employment opportunities in downstream industries, ultimately contributing to the industrialization of local communities and the country at large.

Solution-oriented development of the sound environment in industrial workplaces

Objectives. Research literature has not given much evaluation to why the proposed noise control actions in workplaces are not being implemented. There are views of the different personnel groups in the workplace and the reasons why the possibilities for solutions have not been examined. Methods. The companies under study were a welding machine shop, an assembly plant, a heavy steel company and an art glass factory. Noise management was approached by combining the perspectives of technology, acoustics and occupational safety with the examination of sociocultural factors at the workplace level. Results. Noise was not well represented in occupational safety practices. The productivity aspect was strongly emphasized. The use of personal protective equipment created the illusion that everything possible has been done and noise controlled. Conclusion. The study developed a model in which experts in the field of acoustics and sociocultural researchers together evaluated the state and development needs of noise abatement. The results of the project show that successful noise control solutions require a process involving all staff in the workplace.

Experimental investigation of machine vibration rate and machine sound level in MQL turning of AISI 1525 steel employing mango oil as lubricant

AbstractThe detrimental effects of mineral oil on the environment and machine shops have led to a surge in the usage of vegetable oil as cutting fluid. The most popular vegetable oil lubricants are edible, and they have a lot of potential to rival human consumption eventually. The study examined using mango oil, an inedible vegetable oil, as a lubricant during AISI 1525 steel turning with tungsten inserts. The best machining parameters were ultimately found using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) after the experimental studies were analyzed using the Taguchi process. Surface and contour plots were employed to investigate how different cutting settings affected the rate of vibration and sound level of the machine. Mango kernel seed oil outperformed its mineral oil counterparts by 2.3% and 57.7%, respectively, in terms of machine vibration rate and machine sound level. Moreover, feed rate (0.10 mm/rev), depth of cut (0.75 mm), and spindle speed (350 rev/min) are the ideal cutting settings to reduce machine vibrations and sound intensity. Mango oil holds significant potential as a substitute for cutting fluid derived from petroleum. The significance of this research is to formulate lubricants for industrial use that are more ecologically friendly and sustainable.

Analysis of the Impact of Cooling Lubricants on the Tensile Properties of FDM 3D Printed PLA and PLA+CF Materials.

This study investigates the impact of infill density on the mechanical properties of fused deposition modeling (FDM) 3D-printed polylactic acid (PLA) and PLA reinforced with carbon fiber (PLA+CF) specimens, which hold industrial significance due to their applications in industries where mechanical robustness and durability are critical. Exposure to cooling lubricants is particularly relevant for environments where these materials are frequently subjected to cooling fluids, such as manufacturing plants and machine shops. This research aims to explore insights into the mechanical robustness and durability of these materials under realistic operating conditions, including prolonged exposure to cooling lubricants. Tensile tests were performed on PLA and PLA+CF specimens printed with varying infill densities (40%, 60%, 80%, and 100%). The specimens underwent tensile testing before and after exposure to cooling lubricants for 7 and 30 days, respectively. Mechanical properties such as tensile strength, maximum force, strain, and Young's modulus were measured to evaluate the effects of infill density and lubricant exposure. Higher infill densities significantly increased tensile strength and maximum force for both PLA and PLA+CF specimens. PLA specimens showed an increase in tensile strength from 22.49 MPa at 40% infill density to 45.00 MPa at 100% infill density, representing a 100.09% enhancement. PLA+CF specimens exhibited an increase from 23.09 MPa to 42.54 MPa, marking an 84.27% improvement. After 30 days of lubricant exposure, the tensile strength of PLA specimens decreased by 15.56%, while PLA+CF specimens experienced an 18.60% reduction. Strain values exhibited minor fluctuations, indicating stable elasticity, and Young's modulus improved significantly with higher infill densities, suggesting enhanced material stiffness. Increasing the infill density of FDM 3D-printed PLA and PLA+CF specimens significantly enhance their mechanical properties, even under prolonged exposure to cooling lubricants. These findings have significant implications for industrial applications, indicating that optimizing infill density can enhance the durability and performance of 3D-printed components. This study offers a robust foundation for further research and practical applications, highlighting the critical role of infill density in enhancing structural integrity and load-bearing capacity.

Compósito à base de polipropileno reciclado para utilização em instalações agrícolas

ABSTRACT This study aims to develop an eco-friendly, recyclable, and cost-effective composite material for use in storage sheds and machine workshops. The new composite consists of stone dust and gravel bricks bonded by recycled polypropylene through heat treatment. The main focus of this study is to determine the effects of varying polymer proportions on the resistance and permeability properties of the studied composite, intending to achieve optimal properties, i.e., high resistance and low permeability. To do this, the 2² factorial arrangement was employed, comprising four treatments along with three central points, each replicated three times. The data was statistically analyzed at a 95% confidence level from an adapted methodology. This involved tests of compression strength, 3-point bending strength, Los Angeles abrasion, and water absorption by immersion, in which three percentages of polymer content (PC) - 15, 25, and 35% - and aggregates (fine sand, medium sand, and coarse sand - FS, MS, and CS) were used to prepare the composite. The developed composite was deemed suitable for use in storage warehouses and machine workshops, as it presented physical and mechanical appropriate characteristics, i.e., a low water absorption rate and high resistance to compression and abrasion, in addition to being an environmentally friendly composite.

Analysis and control of occupational safety risks using the HIRARC method in the Machining Workshop

This qualitative study focuses on occupational safety and health in vocational school machining workshops to identify significant risks related to training practices. Workplace accidents are considered a serious threat to workers and equipment, potentially affecting productivity and environmental safety. Observations at several vocational schools, especially at SMK Negeri 1 Batipuh, showed low student awareness and compliance with OHS regulations, increasing the risk of risky behaviour and accidents. To address this, the research used the Hazard Identification, Risk Assessment, and Risk Control (HIRARC) method, which systematically identifies hazards, evaluates risks based on severity and likelihood, and proposes control measures. The research at SMK Negeri 1 Batipuh involved direct observation, interviews, and analysis of SOPs in the workshop, finding significant risk variations in workshop conditions, lathe operations, welding, material handling, hand tool use, and machine protection. The results highlighted the predominance of intermediate risks in all-hazards analyzed, emphasizing the importance of developing more effective risk management strategies. This research aims to reduce accidents and improve student safety during training by addressing existing OHS implementation gaps and implementing appropriate risk controls. In addition to filling a gap in the literature, this study provides practical insights for improving OHS practices in vocational schools.

Perhitungan Ongkos Pemesinan Konvensional Menggunakan Macro Vba Excel pada Studi Kasus (Produk Roda Gigi Payung Ø65mm × Z24)

In the conventional machining process, production costs are essential to know to determine the cost of making a product in any industrial manufacturing such as the SMK N 2 PEKANBARU machining workshop. Machining production costs are calculated based on machining time per product and machining operation costs. In calculating conventional machining costs, the VBA Excel macro is an application that can be used to calculate production costs. The Ø65mm × z24 umbrella gear product which is the research case study is a product that is machined by two conventional machining processes, namely lathe machining and milling machining. From the results of the research, the cost of conventional lathe machining, namely making gear wheels, is IDR 47,841/product, and the conventional milling process, namely making Z24 gears, is IDR 40,002/product, while the machining cost for lathe mastercam simulation is IDR 33,187/product and the machining cost for milling mastercam simulation is IDR 20,340/product. Machining costs are the product of operating costs per minute (cm) and machining time (tm). So, from the results of calculating machining and production costs, it is known that the product manufacturing costs or production costs for Ø65mm × Z24 umbrella gears are in the range of IDR 111,827 - IDR 146,143/product.

Multi-objective optimization using improved NSGA-II for integrated process planning and scheduling problems in a machining job shop for large-size valve.

This paper studied an integrated process planning and scheduling problem from a machining workshop for large-size valves in a valve manufacturing plant. Large-size valves usually contain several key parts and are generally produced in small-series production. Almost all the parts need to be manufactured in the same workshop at the same time in the plant. Facilities have to handle various items in one order, including different models, sizes, and types. It is a classical NP-hard problem on a large scale. An improved NSGA-II algorithm is suggested to obtain satisfactory solutions for makespan and manufacturing costs, which involve large optimization parameters and interactions. A two-section encoding method and an inserting greedy decoding method are chosen to enable the algorithm. The dynamic population update strategy based on dynamic population update and the adaptive mutation technique depending on the population entropy changing rate are selected for enhancing both the solution quality and population diversity. The methodology was successfully implemented in a real-life case at a major valve machining workshop operated by Yuanda Valve Company in China. By taking into account realistic factors and restrictions that have been identified from a real-world manufacturing setting, this technique aids in bridging the knowledge gap between present IPPS research and practical valve production implementations.

Performance Assessment of Quenchants on Mechanical Properties of Steel Grade A1046

The main aim of the study is to assess the performance of ghee oil, coconut oil and sea water quenchants on mechanical properties of A1045 steel. The procedures comprise the production of tensile steel specimens, heat-treat them into electrical oven at 850°C for one hour, quench them in ghee oil, coconut oil and sea water separately. The quenched samples were again tempered separately at the temperature of 400°C. Then all the specimens taken for the mechanical tests such as hardness, tensile, impact test and also to calculate the percentage of elongation, having completion of tests, microstructural analysis had conducted to view the structures contain in each specimen. The results obtained on these processes determine whether these oils can be used as local industrial quenchants. The facilities required for the research is include material testing laboratory, heat treatment workshop, machine shop and metallographic laboratory to mentioned but a few. The material selection is steel grade A1045, that have been normally utilize in metal industries for the production of machine parts and structural components

Effect of Strain Hardening on Burr Control in Drilling of Austenitic Stainless Steel

Austenitic stainless steel has been widely used in various industries, such as aerospace, medical, and hydrogen energy, due to its high strength over a wide range of temperatures, corrosion resistance, and biocompatibility. However, stainless steel is a difficult-to-cut metal because its ductility and low thermal conductivity induce a strain hardening with significant plastic deformation at high temperatures. Burr formed at the back side of a plate is a critical issue which deteriorates the surface quality, especially in drilling. Burr removal operation, therefore, should be done in the machine shop. This study discusses the effect of strain hardening of austenitic stainless steel, SUS 316L, on burr formation. Hardness and cutting tests were conducted to compare the strain hardening effect for three types of workpieces: as-received, pre-machined, and tensile treated specimens. In the employed specimens, the tensile treated specimen is harder than the as-received specimen. Those specimens have uniform hardness in the depth direction from surfaces. Pre-machined specimen, in which the back side of the plate was finished by face milling, has a distribution of hardness in the depth direction from a surface. The highest hardness appears in the subsurface of the pre-machined specimen. The cutting forces in the steady processes, in which the entire edges remove material, were nearly the same as the tested specimens each other. However, remarkable differences were confirmed in the chip thickness and burr formation. The higher strain hardening of the tensile treated specimen is effective to suppress burr formation. The cutting characteristics are then identified to associate burr control with the shear plane model of orthogonal cutting using an energy-based force model. The shear stresses, shear angles, and friction angles of the tensile treated and as-received specimens are compared to discuss the effect of strain hardening on reduction of burr formation.

Precise Enough For Outer Space

Abstract For manufacturers, the ability to produce parts from designs reliably is critical. Because simple blueprints don’t convey enough information, Geometric Dimensioning and Tolerancing, or GD&T, has become a standard symbolic language for communicating properties such as form, location, orientation, size, and function. The ASME Video Production Team recently visited GT Machine and Tool Co. in Long Island City, N.Y., to talk with company president Dean Theodos about how GD&T enabled its machine shop to produce all kinds of parts.

An improved memetic algorithm for multi-objective resource-constrained flexible job shop inverse scheduling problem: An application for machining workshop

Resource-constrained flexible job shop scheduling problems are commonly encountered in some manufacturing industries, and have been widely studied in recent years. However, traditional resource constrained flexible job shop scheduling problem rarely consider the uncertainties in actual manufacturing systems, which may make the original schedule become suboptimal or even unfeasible. Therefore, a resource constrained flexible job shop inverse scheduling problem (RCFJISP) is proposed in this paper, which aims to cope with uncertain events by simultaneously adjusting the machine, worker and process parameters of the original schedule. A multi-objective optimization model is constructed to minimize the makespan, worker cost, machine energy consumption and deviation index. Furthermore, an improved memetic algorithm (IMA) is developed for solving the proposed problem. In IMA, a novel double-layer encoding mechanism is designed to enhance the capacity in exploring new solution’s domains. Three initialization strategies utilizing original scheduling information are designed to improve the quality of initial solutions. An adaptive mutation strategy and a local search mechanism are designed to enhance exploration and exploitation ability of the algorithm. And a crowding operator is proposed to reflect the diversity of the population effectively. In computational experiments, 28 extended benchmarks are constructed, and the effectiveness of the proposed strategy and algorithm is verified by comparing IMA with its 4 variants and other 4 widely used algorithms. Finally, two inverse scheduling problems of a real-world hydraulic cylinder machining workshop under two uncertain situations are studied. The results demonstrate that IMA can effectively solve the actual inverse scheduling problem. With a slight adjustment to the original scheduling, it can reduce the makespan by 11.5%, the worker cost by 8.1% and the machine energy consumption by 27.9% on average.

Prediction model for vertical distribution of oil particles under thermal plume and displacement ventilation in a machining workshop

Oil particle concentrations exhibit an inhomogeneous distribution in large-space machining workshops with a displacement ventilation system. The inhomogeneous distribution can lead to variations in the required supply air volume used to control the indoor particle concentration at different heights. To rapidly calculate the particle concentration distribution in the vertical direction, this study established a zonal particle concentration prediction model based on the mass and energy balance by considering the interaction between the heat source thermal plume, wall thermal plume, and supply airflow. An experiment was conducted in a scaled chamber to validate the proposed prediction model. The result showed that the relative error between the prediction model and experiment ranged from −17% to 10%. A case study was performed to demonstrate the applicability of the prediction model to the control of a displacement ventilation system. Using the prediction model, the control system can maintain the particle concentration in the work area below 0.5 mg/m³with variable particle source emission rates and reduce the supply air volume by at least 24% and 55% compared with the variable and constant air volume systems, respectively, neither of which can address the inhomogeneous distribution of oil particle concentration. The prediction model can also be used for the design of displacement ventilation systems when the inhomogeneous particle concentration distribution is considerable.

Research on data mapping and fusion method of ship production workshop based on digital twins

Aiming at the problems existing in discrete manufacturing workshops of ships, such as the lack of real-time management and control ability of on-site production status, and the long time delay of real-time interaction and fusion between physical entities and virtual entities data, this paper proposes ship production workshop data mapping and fusion method based on digital twins. Taking a ship machining workshop as an application research example, the integrated business process and data mapping and fusion method of the machining workshop based on digital twins are studied. On this basis, the dynamic scheduling optimization algorithm of ship machining workshops based on digital twins is studied. The results show that the data mapping and fusion method in this study can significantly reduce the time delay of data interaction between the virtual and real objects. It can effectively improve the real-time and production flexibility of dynamic and complex tasks such as emergency insertion and task rework. The ability of real-time data interaction and synchronous real-time mapping between physical entities and virtual entities in dynamic scenes such as production line reconstruction and customized production is improved.

Research on Workshop Layout Optimization Based on SLP Method

With the rapid development of the market economy and the increasing personalized needs of customers, the production mode of the production workshop is gradually shifting towards small batch and multi batch production mode, which has a significant impact on the production efficiency, logistics costs, and other aspects of the production workshop, posing huge challenges to the layout of production workshop facilities. A reasonable workshop layout can not only reduce the distance and cost of material handling, but also save product production time and shorten the production cycle. This article takes DY Company's machining workshop as the research object, and through investigation, it is found that there are problems such as logistics distribution routes crossing and overlapping in the workshop. In response to the above issues, data was collected from the workshop and analyzed using the SLP method, ultimately obtaining the optimal solution for optimizing the layout of the machining workshop, achieving a dual improvement in the production capacity and efficiency of the machining workshop.

Incorporating Engineering Skills Training in Engineering Programs

In recent years, shop training in Canadian public schools has declined. Coupled with the steadily decreasing cost of/increased exposure to new manufacturing techniques, many novice engineering students do not know/appreciate the role of machining in design and manufacturing. This deficit in understanding of manufacturing processes, their abilities and deficiencies, and their role in design is a significant weakness. A short duration activity was created to introduce students to various operations on lathes, mills, and drill presses through the manufacturing of a small keychain. During each session, a pair of students entered the machine shop every 10 minutes and moved through the machining processes with their keychain blanks assembly-line style. Feedback was collected from both student participants, and TA supervisors to inform continuous improvement of the activity. Results indicate that students perception of skill as well as their comfort level on the lathe, mill and drill press all increased. Results also demonstrate that there is an increase in student interest in machining after the completion of the keychain activity. Response from TAs indicated that while supervising the activity was a significant burden on them, overall it was worth it for the student participants.

The influence of ventilation modes on oil mist particles diffusion in a machining workshop

Mechanical processing and operations are widely involved in modern industry. Large amount of oil mist is tended to be produced and will diffuse in the processing workshop when metalworking fluids are applied on the high temperature workpiece. The ventilation modes and air distributions can influence the air pollutants dilution in machining workshops. Therefore, this paper presents both experimental investigation and simulation study on the oil mist particles diffusion under different ventilation modes. The results identified PM2.5 as the primary component among different oil mist particles generated during a typical machining process. The distribution of oil mist particles in a full-scale machining workshop laboratory was investigated under two ventilation modes: high-sidewall nozzle air supply and low-sidewall air supply. Results revealed obvious influences of both air supply modes on the distribution of oil mist particles. Under the high-sidewall-nozzle air supply mode, the airflow and the oil mist distribution in the workshop was relatively uniform; while the low-sidewall-vent air supply mode led to an uneven distribution of oil mist particles, and the maximum oil mist concentration appeared at the height of 3 m. Under both modes, the attempts to increase the airflow rate are not always successful. Compared with low-sidewall-vent air supply mode, the high-sidewall-nozzle air supply mode presents better performance in achieving lower overall particle concentration level. Overall, the results of this study give useful reference to improve the air quality of industrial plant by properly designing the ventilation mode of machining workshop.